If you’ve ever tried to audit your website’s speed or SEO performance, you’ve probably come across both PageSpeed Insights and Lighthouse. And like many others, you might be wondering:
- Are these two different tools?
- Should I use one over the other?
- Why does Lighthouse redirect me to PageSpeed Insights?
Let’s clear up the confusion with a straightforward explanation, backed by facts every website owner or SEO professional should know in 2025 and beyond.
The Short Answer
PageSpeed Insights (PSI) is the user-friendly front-end tool, while Lighthouse is the underlying engine that actually performs the audits.
Whenever you test a website on PageSpeed Insights, Google is running a Lighthouse audit in the background and showing you the results in a simpler format.
Why the Confusion Happens
Historically, Lighthouse was used mostly by developers through Chrome DevTools or the command line. As Google integrated it into more tools like PageSpeed Insights, users started seeing Lighthouse-powered results without realizing what Lighthouse actually was.
Important Facts Everyone Should Know
1. PageSpeed Insights uses Lighthouse behind the scenes
Since November 2018, PageSpeed Insights has used Lighthouse to run its tests. You may not see it immediately, but Lighthouse is what powers the metrics and suggestions you see.
2. Google updated PageSpeed Insights in 2021 to show this
The UI redesign in 2021 made it clearer that PageSpeed Insights is powered by Lighthouse, but not everyone noticed the change.
3. Lighthouse gives you more control
By using the Lighthouse tab in Chrome DevTools, you can run tests on staging sites, throttle internet speed, simulate mobile devices, and test for more than just performance—such as accessibility, SEO, and PWA compatibility.
4. PageSpeed Insights is perfect for quick, public tests
It’s simple, fast, and available to everyone. Just paste a URL into PageSpeed Insights, and it will generate a full Lighthouse report without needing any technical knowledge.
5. The Mobile-Friendly Test tool was discontinued in 2023
The Mobile-Friendly Test tool was officially retired by Google on December 1, 2023. This decision was part of a broader move that also included the discontinuation of the Mobile Usability report and the Mobile-Friendly Test API.
6. Both tools are developed and maintained by Google
You’re not choosing between tools made by different companies. Lighthouse and PageSpeed Insights are both Google products—PageSpeed just uses Lighthouse in the background.
When Should You Use Each Tool?
| Use Case | Best Tool |
|---|---|
| Checking live, public website speed and Core Web Vitals | PageSpeed Insights |
| Testing private or local/staging websites | Lighthouse in Chrome DevTools |
| Running advanced tests (network throttling, offline mode, accessibility) | Lighthouse in Chrome DevTools |
| Automating performance audits in development pipelines | Lighthouse via CLI (Node.js) |
How to Open the Lighthouse Tool in Chrome
- Open your website in Google Chrome
- Right-click and select “Inspect”, or press Ctrl + Shift + I (Cmd + Option + I on Mac)
- Click the “Lighthouse” tab in DevTools
- Choose device type (Mobile or Desktop) and categories (Performance, SEO, etc.)
- Click “Generate Report” to run the audit
You’ll get a detailed report similar to what PageSpeed Insights shows, but with more flexibility.
Final Thoughts
The next time someone says “Use Lighthouse,” remember that you probably already are—especially if you’re using PageSpeed Insights.
- Use PageSpeed Insights for quick and accessible performance tests
- Use Lighthouse (in Chrome DevTools) when you need deeper insights or want to audit local, private, or more complex setups
Understanding the connection between the two helps you use each tool more effectively—without any confusion.
